BRPI0615403A2 - methods for in-situ slot formation in a soderberg anode - Google Patents

Abstract

METHODS FOR IN-SITU SLOT TRAINING IN A SODERBERG ANOD. The present invention relates to a self-cooking Soderberg type carbon anode (40) for use in an aluminum electrolysis cell (1) to form aluminum product, in which the anode (40) is consumable in molten electrolyte ( 12) in the cell, the anode having top, bottom and side surfaces, and multiple layers of plate inserts (48) arranged vertically, fused in the molten electrolyte, the plate inserts (48) preferably made of aluminum and are capable of melting to create hollow grooves (52) in the bottom of the anode facilitating any gas bubbles (60) generated to channel to the side of the anode within the electrolyte.

Description

Invention Patent Descriptive Report for "METHODS FOR IN-SITU TRAINING IN A SODERBERG ANODE".

Related Order Cross Reference

This application claims priority for US Patent Application No. 911 / 215,586 filed August 30, 2005, which is incorporated herein by reference.

Field of the Invention

The present invention relates to the use of self-baking carbon anode grooves for use in aluminum electrolysis cells, wherein the grooves channel anode gas out of anode surfaces.

Background of the Invention

Aluminum is conventionally produced by dealumin electrolysis dissolved in cryolite-based molten electrolytes (usually as NaF plus AIF3) at temperatures between approximately 900 ° C and 1000 ° C, the process is known as the Hall-Heroult process. A Hall-Heroult "electrolytic furnace" reduction cell typically comprises a steel housing having an insulating coating of refractory material which in turn has a carbon coating that contacts the molten constituents. Conductive bars connected to the negative pole of a continuous flowing source are embedded in the carbon cathode substrate that forms the bottom floor of the cell. In general carbon anodes are consumed with the evolution of carbon oxide gas (CO2 and CO), such as gas bubbles and the like.

There are two anode technologies used to produce aluminum by the Hall-Heroul electrolytic process. One is a pre-cooked anode characterized by US Patent No. 2,480,474, mentioned above, and US Patent Application Publication No. 20050199488, filed March 11, 2004 (Barclay et al.). The other is a "Soderberg" self-etching anode cell technology characterized by US Patent No. 93,996,117 (Graham et al.). In a precooked cell, there are usually between 10 and 40 anodes, depending on cell size (amp). Soderberg's cells have only one large self-anode having an approximate size of 2 to 3 meters in width and 5-6 meters in length. This self-anode anode is designed by Sodenberg in US Patent No. 91,440,724.

As described by Edwards et al. in Aluminum and Its Production.McGraw-HiII1 New York1 1930, pp. 25-30. 300-307, carbon anodes may be made from a mixture of carbon, tar and tar, which is pressed into molds and subsequently baked in a baking oven, or they may be made by Soderberg's technique. In Soderberg's technique, a steel casing is used to maintain a carbonaceous paste of carbon and tar-tar electrode. The electrode mixture is gradually cooked to provide a good conductivity dense cooked carbon electrode that is gradually moved toward the electrolytes, where it is eventually consumed.

Carbon anode consumption in fused electrolytes is shown in US Patent Specification Nos. 2,480,474 and 3,756,929 (Jonhson Figure 6a and Schmidt-Hatting et al. Figure 1, respectively). The anodes are at least partially submerged in the bath and those anodes as well as their supporting structures are regularly replaced once carbon is consumed. Alumina is fed into the bath during cell operation and it is important to have good alumina dissolution. Anode gas bubbles will help create / cause bath flow and turbulence. It is important to create good turbulence by the favorable anode gas bubbles to increase alumina dissolution.

Traditional technology has relied on the natural flow of gases from under the carbon anodes during the aluminum reduction process, but this has delayed the removal of gas bubbles and diminished aluminum efficiencies and production. This presence and accumulation of gas generated during electrolysis has been a continuing problem in the industry and a cause of high energy demands, and to operate the electrolysis cells, the electrodes must be designed properly. With their large surface area In the background, the Soderberg anodes can present serious problems in gas evolution. In a self-sizing Soderberg-type electrolysis cell during electrolysis,

A large amount of anode gas (40 to 50 kg CO2 / hour) is produced on a single anode bottom surface, and the anode gas must travel a considerable distance before it can be released from the anode bottom surface. Gas bubbles coalesce and grow even larger before they escape the large anode bottom surface. This process of anode gas bubble formation, coalescence, and freeing / escaping anode surfaces create significant cell instability, and therefore, Soderberg cells usually have lower current efficiency than pre cells. -baked. At the same time, anode gas bubbles cover a large percentage of the deep anode surface, which results in a significant increase in the electrical evolution of the cell, resulting in a higher energy consumption than precooked cell technologies. For example, U.S. Patent No. 3,996,117 (Graham et al.) Discloses a carbon block anode disposed between a steel jacket in which an anode gas primarily is substantially trapped under an alumina-containing crust. In US Patent No. 5,030,335 (Olsen), trapped CO2 gas was recognized as a problem during the passage of CO2 to a tailings burner, as the gas could also contain tar volatiles and the product of combustion could have been moistened or dry cleaned. Also, crust breaks could allow gas to escape in the furnace construction. In Olsen, a plurality of lifting plates were used as seals. In Olsen, the side steel / collector jacket for the Soderberg anode is shown most clearly. Neither of these two previous Soderberg cell designs solves anode-bottom CO2 formation problems.

What is needed is a So-derberg carbon anode design that will quickly channel anode gas off the bottom horizontal surface to improve cell current efficiency, increase cell stability and reduce electrical resistance. Summary of the Invention

It is a main object of the invention to provide a Soderberg cell / anode design that reduces the amount of gas bubbles on the bottom surface of self-baking Soderberg anodes.

The above needs are met and the objective accomplished by providing a series of plate inserts and corresponding slots in a Soderberg anode. In one aspect there is provided an aluminum electrolysis cell having such a Soderberg anode, the consumable So-derberg type carbon anode in molten electrolyte, having top, side bottom surfaces, with vertical metal pins leading electrically disposed within the anode body, the anode operating on a fused electrolyte in an aluminum electrolysis cell, where gas bubbles are generated on the anode bottom surface, where the anode is moved in a vertical direction downward on an electrolyte while the anode is consumed, and in that the anode has a plurality of outer grooves at the bottom of the anode surface along a horizontal axis of the anode. The slots are exposed to molten electrolyte and are configured to allow anode gas bubbles to pass out of the electrolyte and away from the anode without capping the scratches. The anode includes a plurality of plate insert layers or columns, plate inserts comprising at least one aluminum, aluminum oxide, cryolite and mixtures thereof, where the bottom layer of the inserts will melt / dissolve with downward motion. anode within the molten electrolyte to form grooves at the bottom of the anode contact with the electrolyte.

The anode grooves may be of any orientation (e.g., a vertical orientation) and are generally non-continuous. Non-continuous cracks are formed at the Soderberg carbon anode in detail so that bubbles and coalesced bubbles generated on electrolyte surfaces flow into the grooves and the grooves promote bubble movement outward from the center of the anode bottom surface and toward the side of the anode. In this regard, the plate inserts may be of appropriate size to realize the desired slot size with respect to width, length and height. The width of the plate inserts (hence the width of the slot) can be selected such that they allow continuous channeling of a significant amount of anode gas and an appropriate gas flow rate. Preferably, the cracks will not collapse or become plugged with anode gases. The height of the plate insertion decides the depth of the aqual groove dictates the life span of each groove. For example, the width of the grooves (plate insert thickness) may be approximately 0.75 cm to 1.5 cm, preferably 1.0 cm to 1.3 cm for conventional Soderberg style anodes. At conventional Soderberg anodes, the height of the plate insertion can be between 6 cm and 50 cm, preferably 9 cm to 20 cm, which can produce grooves remaining 6 days to 14 days at conventional carbon anodes. The length of the plate inserts depends on the width of the Soderberg anode. The strength and integrity of the anode carbon are also taken into account.

The plates forming grooves at the top can be positioned between the billet columns / steel pins / anode clamps. The cracks should thus be formed / located at the locations between the billet columns / anode clamps (not touching the billets). To ensure that the number of slots is sufficient during operation, the insertion plates can be inserted between each other column of pins (alternating between inserting plates between adjacent steel anode billet columns).

In another aspect, a self-baking Soder-berg type carbon anode is provided, the anode having top, bottom and lateraise surfaces containing a plurality of vertically disposed plate insert layers, plate inserts comprising at least one aluminum, oxide aluminum, cryolite and mixtures thereof, the plate inserts being able to fuse to create the grooves at the bottom of the anode thereby allowing any gas generated in the anode operation to pass through the grooves to the anode side. In one embodiment, the plate inserts are aluminum or a low impurity aluminum alloy. Thus, the anode may include a plurality of plate inserts surrounded by carbon-based anode material. Plate inserts may be arranged at various vertical levels within the anode. For example, plate inserts may be arranged in four distinct layers within the anode. The layers of plate inserts may be distinct or the layers may be juxtaposed, such as along a horizontal axis of the anode, (for example, a first set of plate inserts may be arranged around a first horizontal axis and a second set of insertions. may be arranged around a second horizontal axis, the distance between the two horizontal axes being shorter than the length of a plate insert assembly). Plate inserts may be aligned in a vertical direction, wherein a plurality of plate inserts are aligned with a first horizontal axis of the anode, (for example, a first set of plate inserts may be aligned. with a first vertical axis and a second set of plate inserts may be aligned with a second vertical axis. In a particular embodiment, the anode includes at least four distinct layers of plate inserts, each layer including a plurality of inserts. The anode may also include a plurality of slots located near the bottom of the anode The slots are formed by fusing the plate inserts as described.

In another aspect, methods of forming a Soderberg anode are provided, the methods including the steps of adding carbon paste to an upper portion of a shell containing a Soderberg anode; insert plate inserts into the carbon paste, and lower the carbon paste toward the molten electrolyte. The methods may include the step (s) of adding carbon paste to the top of the housing and / or inserting additional plate inserts into the carbon paste. Any of the above steps may be concomitant with the step of producing aluminum with an aluminum electrolysis cell interconnected to the Soderberg anode. Number of plate / slot inserts and plate / slot insert configurations may be selected to effectively and efficiently constrain formation. large gas bubbles and channel the anode gas out of the anode surface during the operation of an electrolytic cell, thereby enhancing the cell's current efficiency and cell stability. Also, reducing the amount of gas bubbles on the deep surface of the Soderberg anodes will significantly reduce electrical resistance, lower the total cell voltage, and thereby reduce the cell's electrical power consumption. Methods of producing α-lumenium using the Soderberg anodes described above are also provided.

As can be seen, several of the above aspects or approaches can be combined to produce various inventive carbothermal production systems and methods. These other aspects, advantages, and novel features of the invention are set forth in part in the following description and will become apparent to those skilled in the art by examining the following description and figures, or may be learned by practicing the invention.

Brief Description of the Drawings

A complete understanding of the invention may be appreciated by the following Detailed Description of the Invention when read with reference to the accompanying drawings in which:

Figure 1 is a partially broken cross-sectional view of a traditional prior art self-sealing Soderberg anode type cell similar to that illustrated in Patent Specification 3,996,117;

Figure 2 is a schematic partially broken away cross-sectional front view of part of a self-sealing Soderberg anode-type cell showing a plurality of grooves and aluminum plate inserts embedded within the anode;

Figure 3 is a schematic partially broken down cross-sectional side view of the cell shown in Figure 2;

Figure 4 is an enlarged partial view of the operating part of Figure 3 showing the transition anode in an aluminum electrolysis cell where a groove is formed after an aluminum plate insert is fused, and where the surrounding carbon anode, shown as a dashed line, it is producing bubbles and these bubbles flow into the groove for ease of bubble removal.

Figure 5 is a schematic cross-sectional top-view view of a self-sealing Soderberg anode showing a position of aluminum plate inserts on two vertical levels of the anode.

Figure 6 is a comparative graph of the voltage (V) noise of the Soderberg cell anode electrolyte furnace, with traditional Soder-berg anodes. grooved Soderberg anodes;

Figures 7 (a) and 7 (b) are comparative graphs of typical anode potential vs. time showing results of gas-cap size and release formation on anode surfaces of traditional Soderberg anodes and grooved Soderberg anodes;

Figures 8 (a) and 8 (b) are comparative graphs of the electrolytic furnace cell voltage (v) vs. time showing voltage fluctuation of a traditional Soderberg anode cell and a grooved Soderberg anode cell; and

Figure 9 is a comparative graph of the gas drop voltage drop as measured on cracked and slotted Soderberg anodes.

Detailed Description of the Invention

Figure 1 illustrates a traditional self-etching Soderberg-type carbon-based anode 13 operating on molten electrolyte 12 in an aluminum electrolysis cell 1. This cell 1 includes a steel housing 10, a molten aluminum metal product vat 11 and an electrolyte tubing 12. Anode gas bubbles (mainly CO2) appear as large bubbles trapped 2 at the bottom 3 of anode 13, coalesce into larger bubbles 4 near the side 5 of anode 13 and finally releasing large bubbles 6 moving upwards as shown in arrow 7. Suspended in bath 12 is a Soderberg anode (+) 13. Associated with the Soderberg anode are metals, usually clamps / leads / pins 14a, 14b and 14c, which are connected to the positive side of an electrical current source. A metal is usually provided, steel jacket 15, upper anode nipple, where the anode constituents have not yet hardened sufficiently (uncooked) to make them self-supporting. While the anode is consumed as shown by the bottom irregular 3, it is moved down into the electrolyte as shown by the top-up arrow 17.

Surrounding the anode a collector 16 may be used to provide an upper side to the porous crust 28 and to promote smoke collection usually through a traditional (not shown) exhaust burner. Cast aluminum tub (or platform) 11 is supported on carbonaceous block liner 19 and punched carbonaceous liner 20. Carbonaceous linings can be supported on an aluminum filler 21. Optionally, it can be interposed between the liner and the floor tile. stone 22. A layer of red brick 23 may be placed next to stone tile 22. A mica material 18 may be used for the purpose of providing an extra degree of safety against current flow through cell 10.

The cathode current is supplied through steel bars 24, the carbonaceous block coating 19. The current supply is indicated by plus and minus signs at anode 13 and the connector bar 24 respectively.

A plate 25 provided over the upper edge of the steel housing may serve the purpose of protecting the carbonaceous coating when the porous crust 28 is being ruptured for the purpose of feeding additional aluminum to the bath 12. The crust 28 is formed of loose particles of carbon. α-lumine 29a. On its underside, the crust becomes, in part, an alumina rich materialsinterized 29b. Operating parameters are selected such that a grasped layer 30 of alumina and bath limits the sides of aluminum metal bowl 11 and bath 12. It is preferred that the bed 30 extends at least down to the bottom of the slope. of the punched coat 20.

As shown in this prior art Soderberg anode, both bottom 3 and side 5 are flat, and bubbles 2 and 4 are essentially trapped under the anode side between the positive and negative poles in a semicontinuous bubble layer. In order to facilitate the release of this bubble, the Soderberg anode shown in Figures 2-5 was developed.

As shown in Figures 2-5, this new and improved self-baking Soderberg-type carbon-based anode 40 has top 42, bottom 44 and side surfaces 46, the bottom surface 44 contacting and being immersed in molten electrolyte 12, usually a Na3AIF6 cryolite nabase electrolyte (NaF + AIF3) which will operate at a temperature of approximately 800 ° C to approximately 1100 ° C, usually from 900 ° C to 1000 ° C. An aluminum tub (or platform) 11 produced is formed below the molten electrolyte 12, the aluminum also acting as the cathode. The cathode connector bar is shown as 24 and the metal anode conductors as 14. The Soderberg 40 anode can be made either. such as wet pastes typically comprising 20% by weight to 30% by weight of coal tar / oil tar and 70% by weight to 80% by weight of calcined petroleum coke. Also shown in Figures 2-5 are anode metal conductors, such as steel clamps / dowels / pins14 (hereinafter "pins"); metal, such as steel anode casing / jacket 15. Also shown is casing 20, the bottom of which may have a connector bar 24. Anode beam 57 for raising or lowering anodes is also shown in Figures 2 -3. The bottom edge of the groove is shown as 63 and the surrounding anode of the groove is shown as 40.

As shown in Figures 2-4, plates, plates, or inserts containing fusible aluminum, here after "plate inserts" 48 are disposed within anode 40 as layers or columns along the horizontal axis, such as axis 66, and a plurality of vertical levels 50. These plate inserts are able to fuse, while the bottom 44 of anode 40 cooks molten cryolite 12, to create vertical outward hollow grooves 52, shown here in the idealized form as fully fused, better shown. in the side view of Figures 3 and 4 at the bottom of the anode. Thus the anode gases (e.g., CO2) generated during electrolysis cell operation can easily channel through the open slots 52 to the anode step, as shown in Figure 4.

Plate inserts (e.g. solidified / cast plates / molded plates) may comprise aluminum and any other levels of other materials which, by melting, do not result in unacceptable impurities in the aluminum being produced. Such other materials may comprise various aluminum oxides (for example, one or more of Al 2 O 3; Al 2 O 3 · H 2 O; Al 2 O 3 · 2H 2 O and Al 2 O 3 · 3 H 2 O) such as cast or cast aluminum oxides, and / or cryolite (also cast or cast) As used herein, cryolite includes Na3AIF6, AIF3 and similar additives. Aluminum may be in the form of an alloy, such as an aluminum alloy comprising one or more of Fe, Ni, Cu, Zn, Co, or other metallic materials. For example, the plate inserts may be aluminum, such as consisting essentially of aluminum, or the plate inserts may be a low impurity aluminum alloy, for example an aluminum alloy having less than approximately 0.1% by weight of Fe; less than about 0.02 wt% Ni; less than approximately 0.05% by weight of Cu; less than approximately 0.02% by weight of Zn and / or less than approximately 0.02% by weight of Co, so that when the aluminum alloy melts, the amount of non-aluminum melt components will be commercially acceptable. The use of aluminum plates as a plate material is also desirable in that aluminum will remain a solid during the carbon paste cooking step, which occurs at a temperature of from 300 ° C to 60 ° C.

The height 54, length 56 and width of the inserts 48 may be tailored to the size of anode 40. For conventional So-derberg anodes, the slots 52 and plate inserts 48 generally have a height 54 of from about 6 cm. at 50 cm, preferably 13 cm to 20 cm. For conventional anodes, if plate inserts are below 6 cm, increased labor cost can be verified due to the number of plates that will have to be inserted during cell operation, and for plate inserts above 50 cm, it could be it is possible to bleed the paste if cryolite is used; Also, the integrity of the anode could be at risk. For conventional anodes, the length of plate and groove inserts 56 is generally in the range of approximately 50 cm to approximately 120 cm, depending on the length of the anode side. For conventional anodes, if the length of the plate insert is below 50 cm, most of the anode surface cannot be covered by the grooves, and therefore is not effective. For conventional anodes, the width (thickness) is usually between 0.75 cm and 1.5 cm.

Referring to Figure 4, for a clearer painting of cell operation, a partial enlarged view of the side view of Figure 1 is shown. In Figure 4, anode 40 has been moved downward and completely fuses the insert. of the bottom layer plate providing the heat-slot of the molten electrolyte, which has a temperature greater than the melting point of the plate insert. The molten plate insert falls into the metal plate, and left behind is a rectangular groove, such as groove 52 in Figure 4. This groove 52 channels gas bubbles 60 out of the local anode surface, shown by dashed lines 13 '.

The plate inserts 48 are surrounded by the anode, except that the plate inserts 48 interface with the molten electrolyte 12 so that the anode continues to react with the molten electrolyte, generating bubbles 60 and being consumed. Bubbles 60 will flow into the slots52 left after the plate inserts fuse. Generally, there is growth in large agglomerations of bubbles. Larger bubbles will further grow into a giant blanket type 61. Arrows 7 show the way up the bubbles. In both Figures 1 and 4, when the bubbles leave the electrolyte 12, they become part of the atmosphere above the electrolyte. Also shown are collector 16 and loose alumina particles 29a and sintered alumina rich material 29b.

The carbonaceous block liner 19 contains connection bars 24. The metal pins are not shown in Figure 4 for simplicity. Aluminum plate inserts 48 are interdispersed through anode 40 in no necessarily particular but preferably multi-layered arrangement (e.g., one, two, three, four layers or more) in the vertical columns 64, one below. each other and aligned between pins 14, as best shown in Figure 2. Aluminum plate inserts 48 are arranged between metal pins 14 as shown in Figure 2. As shown in Figure 5, metal pins may be displaced at an angle as shown, where in that situation the plate insertions will also be displaced and generally parallel to the metal studs. In Figure 5, the plate insert assembly 48a corresponds to the top plate inserts 48a in Figure 2, while the plate inserts shown in dashed 48b correspond to the plate insert 48b in the next column and layer. The layer below in Figure 2. End-to-End Insertion Plate 48c may also be used and may be attached to or separated from other inserts.

The grooves 52 may be formed and maintained at the Soderberg anodes by periodically inserting plate inserts 48 into the uncooked carbon anode pad or briquettes at the top of the anodes. The groove forming plates are generally inserted in a substantially vertical position within the carbon anode paste at the top of the anodes between the steel anode pins 14.

As the anode is consumed, plate inserts 48 move downward along with all anode mass. They will melt (leaving free space and groove 52 in contact with electrolyte) and the metal will be recovered from the metal platform as the anode (plate) section moves down into the bath. Plate inserts should not contaminate the metallic quality of aluminum.

Figures 2-4 show where the aluminum plates are inserted from the top of the anode together with anode paste loading and vertical grooves are created as the aluminum metal leaks out into the metal vat below after the anode section moves low and in contact with the molten bath.

In addition to the arrangement of the deep end plate inserts for making vertical grooves in the Soderberg anodes, the specifications of the plate inserts (or slot size) including the number of plate inserts used, the spacing and sizes of the plate inserts are considered. part of the invention. The number of slots / inserts in the Soderberg anode can be tailored to reduce electrolytic furnace noise (for example, by increasing the stability of the electrolytic furnace) and reduce the anode gas bubble voltage drop.

Examples

Shown in Figure 9 is the bubble voltage drop of anode and slotted anode gas at the Soderberg anodes, which is a comparison of the anode gas bubble voltage drop as measured at different locations on the Soderberg anode with and without grooves. Slotted Soderberg anodes are shown as voltages120 and Slotted Soderberg anodes are shown as voltages125. The gas bubble voltage drop at regular Soderberg anodes may be greater than 0.4 V. When grooves are present in the surfaces, the gas bubble voltage drop may be reduced to as low as 0, 15 V, a difference as high as 0.25 V. This is important because this is the voltage saving potential of the electrolytic furnace by inserting slots in the Soderberg anode.

The presence of the grooves reduces the size of the anode gas bubbles before the anode gas releases / escapes from the So-derberg anode surface. Shown in Figure 7 (a) is an anode potential (in reference to an Al metal electrode) responding to repetitive processes of Soderberg anode gas bubble formation - »Coalescence Freezing from the surface where there is no slot. Each peak and valene spectrum represents a cycle of gas bubbles from formation to release. The magnitude of the voltage potential fluctuation, as well as the time taken to fulfill the cycle, determines the size of the anode gas formation prior to its release. When grooves are present on the surface of the Soderberg anode, the size of the anode gas bubbles as well as the processes of anode gas bubble formation and release can be modified. As seen in Figure 7 (b), the magnitude of the anode potential is substantially reduced. The size of the greatly reduced anode gas bubble (Soderberg anode formation and release) under the presence of numerous grooves on the Soderberg anode surface translates into reduced aode gas bubble voltage drop and a more stable electrolytic furnace with reduced noise. .

Shown in Figures 8 (a) and 8 (b) are the fluctuations in voltages with and without grooved Soderberg anodes, respectively. The magnitude of the size of anode gas bubbles also reflects the stability of the electrolytic furnace. (noise). The electrolytic furnace voltage fluctuates from a low value of 4.2 V to a high value of 4.5 V, while mainly influenced by the processes of formation and release of the anode bubbles. The magnitude of cell voltage fluctuation can be significantly reduced with the formation of grooves on the So-denberg surface by interrupting the formation of large gas bubbles on the anode surface. Figure 8 (b) shows a variation in cell voltage vs. time with a substantially reduced magnitude of fluctuation when cracks are present. Cell voltage ranges from a low value of 4.3 V to a high value of 4.4 V. Figure 8 (b) shows a cell voltage time recording having a much smaller voltage fluctuation while influenced by grooves to interrupt the formation and release of gas bubbles on the surface of the Soderberg anode.

Experimental Soderberg anodes containing vertically disposed aluminum plate inserts which melted a hot cryolite bath at approximately 1000 ° C were tested. Non-slotted traditional Soderberg anodes for differences in bubble noise, defined as peak to peak voltage difference of "short term" electrolytic oven. The result indicated that "slotted" Soderberg cells have a greater potential to reduce gas bubble noise due to the larger noise associated with the large size of the single Soderberg anode.

As shown in Figure 6, the electrolytic furnace noise was generally higher in traditional anode Soderberg electrolytic furnaces than a grooved anode electrolytic furnace. Traditional high-noise Soderberg anodes are shown as 100, and traditional low-noise Soderberg anodes are shown as 105, while grooved Soderberg anodes are shown as 110. Electrolytic furnace noise was lower at Grooved Soderberg anode110, (0.04 - 0.05 volts). There was an 80% reduction in electrolytic furnace noise when compared to traditional electrolytic furnaces with a high noise 100, (-0,200 volts). There was a 40% reduction in electro-lithic furnace noise when compared to traditional low-noise electrolytic furnaces 105. This means that on average, the grooves can reduce electrolytic oven noise as much as 0.100 volts. Less electrolytic oven noise also means better electrolytic oven operation and high running efficiency.

While various embodiments of the present invention have been described in detail, it is clear that modifications and adaptations of those embodiments will occur to those skilled in the art. However, it should be expressly understood that such modifications and adaptations are within the spirit and scope of the present invention.

Claims (18)

1. Soderberg self-burnt type carbon anode, consumable in molten electrolyte having top, bottom and side surfaces, wherein the carbon anode has a plurality of plate inserts disposed vertically selected from a group consisting of aluminum, aluminum oxide, cryolite and mixtures thereof, fuse in the decriolite electrolyte, said plate inserts capable of melting to create hollow points at the bottom of the anode, allowing any gas bubbles generated during anode operation to pass through the grooves into the anode. anode side. Carbon anode according to claim 1, wherein the plate inserts are aluminum. Carbon anode according to any one of the preceding claims, wherein the plate inserts are low hardness aluminum, the alloy having less than approximately 0.1 wt% Fe; less than approximately 0.02% by weight of Ni; less than about 0.05 wt% Cu; less than about 0.02% by weight of Zn; and less than about 0.02% by weight of Co. Carbon anode according to any one of the preceding claims, wherein the plate inserts have a height of approximately 6 cm to approximately 50 cm and a width of approximately 0.75 cm to approximately 1, 5 cm. Carbon anode according to any one of the preceding claims, wherein the topmost plate inserts are disposed between the conductive metal pins. Carbon anode according to any one of the preceding claims, wherein the anode comprises coal tar and petroleum puff. An aluminum electrolysis cell comprising: (1) at least one consumable self-sinking Soderberg-type carbon anode having vertical metal composite top, bottom and side surfaces electrically conducting within the anode body; molten electrolyte in which the at least one carbon anode is placed such that the anode bottom surfaces contact the electrolyte to self-bake the anode bottom, and where gas bubbles are generated on the anode bottom surface; (3) means for vertically moving the at least one carbon anode in a downward direction in the fused electrolyte while at least one carbon anode is consumed by the electrolyte; and (4) a plurality of layers of selected plate inserts from a group consisting of aluminum, aluminum oxide, cryolite mixtures thereof, within the at least one carbon anode, whose plate inserts will melt downwardly from the anode. within the molten electrolyte to provide hollow grooves communicating with the electrolyte, the grooves of which can channel gas bubbles from the bottom of at least one carbon anode into the electrolyte. The electrolysis cell according to claim 7, wherein the at least one carbon anode comprises coal tar and petroleum pitch. The electrolysis cell according to claim 7, wherein the molten electrolyte is a molten cryolite bath and the aluminum plate inserts. An electrolysis cell according to any one of claims 7 and 8, wherein the molten electrolyte is a molten cryolite bath and the plate inserts are of a low impurity aluminum having at least about 0.1 µm alloys. % by weight of Fe; less than about 0.02 wt% Ni; less than approximately 0.05% by weight of Cu; less than approximately 0.02% by weight of Zn; less than approximately 0.02% by weight of Co. An electrolysis cell according to any one of claims 7 - 10, wherein the molten electrolyte has a temperature of from about 800 ° C to about 1100 ° C. An electrolysis cell according to any one of claims 7 - 10, wherein the molten electrolyte has a temperature of from about 900 ° C to about 1000 ° C. An electrolysis cell according to any one of claims T-12, wherein the plate inserts have a height of approximately 6 cm to approximately 50 cm and a width of approximately 0.75 cm to approximately 1.5 cm. An electrolysis cell according to any one of claims 7-13, wherein the topmost plate inserts are disposed between the conductive metal pins. An electrolysis cell according to any one of claims 7 - 14, wherein the generated gas bubbles do not coalesce into large bubble clumps at the bottom of the anode. A method of producing a Soderberg anode comprising: adding carbon paste to an upper portion of an interconnected shell to a Soderberg anode, inserting a plurality of fuse plates into the carbon paste; and lower the carbon paste toward the molten electrolyte. A method of producing aluminum, the method comprising: contacting a molten electrolyte with a Soderberg anode, heating the molten electrolyte at a temperature of from about 900 ° C to approximately 1000 ° C, dissolving the plate contained in the anode to form a groove where gases generated during heating of the molten electrolyte may pass through the groove and away from the Soderberg anode. The method of claim 17, wherein the generated gases pass through the slot without capping the slot.